The Communist Party of India (Marxist) on Sunday demanded that the investigation into the police firing in Tamil Nadu’s Thoothukudi should be done by an authority not connected to the state or central governments. Party general secretary Sitaram Yechury said the Central Bureau of Investigation should look into the matter, monitored by the Madras High Court, PTI reported.

Thirteen people agitating against the expansion of the Vedanta Group’s Sterlite Copper plant in the coastal town were killed in firing by security personnel on May 22 and 23. The police have transferred the case to the Crime Investigation Department.

After meeting families of those who died and were injured in the firing, Yechury questioned who gave the orders to shoot at the protestors if the district collector and police chief were not at the headquarters that day. He demanded to know whether the collector delegated the authority to anyone or whether somebody took on that power themselves.

Yechury alleged that the police firing was planned and not a response to provocation as the state government has claimed. “Most of the gunshots hit above the waist, targeting the chest,” he said. “It was certainly not a move aimed at managing the crowd.”

Yechury also said the copper plant was allowed to operate because the Vedanta group had “strong connections” with successive governments. Vedanta Resources is one of the leading donors to both the Bharatiya Janata Party and the Congress, he said, claiming that this had resulted in environmental violations, The New Indian Express reported.

Meanwhile, retired High Court judge Aruna Jagdeesan, who will head the one-woman inquiry committee that will investigate Thoothukudi violence, took charge on Monday. “The people from media who have the unedited video of whatever happened there [in Thoothukudi] have a week’s time to submit it to the officials,” Jagadessan told reporters. “I am going to meet the injured. Their statements will be taken and those who cannot come to the court to record their statements, we will make arrangements.”

The Tamil Nadu government has ordered the closure of the smelter and the State Industries Promotion Corporation of Tamil Nadu has cancelled the land allotted to Vedanta for the proposed expansion of the plant. The Madras High Court has asked the government to explain the reasons and the circumstances that led to the police firing. A petition had demanded that a murder case be filed against the state police chief.

For more than two decades, activists in Thoothukudi have accused Sterlite of contaminating the region’s air and water resources, causing breathing disorders, skin diseases, heart conditions and cancer. Since February, there have been large-scale protests in Thoothukudi, where the Sterlite ran the copper smelter with the capacity to produce 4.38 lakh tonnes of anodes per annum, or 1,200 tonnes per day.